1. Field of the Disclosure
The present disclosure relates to a sound image localization apparatus and a sound image localization method using head related transfer function (HRTF), and to a virtual surround system.
2. Description of Related Art
Many sound field representing techniques that allow a listener who listens to a certain sound with a stereophonic electroacoustic transducer such as a headphone to perceive, with filtering processing, the sound as if the listener were hearing the sound in an arbitrary space have been proposed. Among these sound field representing techniques, as an advantageous method at present, there is a technique, which measures an HRTF at the position of the ear drum and designs filter parameters using the HRTF. When a sound occurs from a particular direction, an HRTF describes a change in sound at the eardrum, which is caused by an object near the eardrum, such as the pinna, head, or shoulder, as a transfer function. A filter is designed using the HRTF, and, when sound is filtered using this HRTF filter, the sound can be perceived as if it were heard from the particular direction. Such processing is called sound image localization processing.
Also, as an apparatus that uses a sound field representing technique, there is a virtual surround system, which downmixes, with a plurality of sound image localization processes, multichannel sound to stereophonic sound without losing surround effects.